The comedy club joined forces with advertising agency The Cyranos McCann, to think up a new strategy for boosting revenue, after an increase in theatre taxes in Spain led to a drastic drop in ticket sales.

So far, the novelty pricing system seems to have been a success. People are rising to, and failing, the challenge of sitting through a laughless comedy show, in order to try and obtain a free ticket.

Consequently ticket prices are up by an average of €6 per person - suggesting more than a few unsuccessful attempts.

However, critics warn that such increased revenue will not be sustainable once the novelty wears off.

In spite of this possibility, it is thought that the new system might be introduced to other venues in Spain.